The accurate measurement of sleep related diseases such as sleep apnea is important to managing the overall health of a person. Sleep Apnea Syndrome (SAS) is a major sleep disorder that causes recurrent episodes of complete (apnea) or partial (hypopnea) blockage of the upper airway during sleep. One of the metrics that quantify the severity of SAS is the Apnea-Hypopnea Index (AHI) index, which is the number of apnea and hypopnea events per hour (EPH) averaged over the duration of sleep. The prevalence of SAS is approximately 3 to 7% in adult men and 2 to 5% in adult women and the disease prevalence in higher in different population subsets such as the obese or older groups. Additionally, there is a large proportion of undiagnosed SAS patients because routine clinical visits and blood tests usually do not detect SAS. Accurate and timely SAS diagnosis is important because there are adverse health consequences of this disorder, including daytime hypersomnolence, neurocognitive dysfunction, cardiovascular disease, metabolic dysfunction and respiratory failure.
Conventional sleep testing and sleep staging of a person is done via cumbersome clinical studies and in-center testing facilities. A polysomnography (PSG) test is the gold standard test for the diagnosis of SAS. The PSG test involves the monitoring during overnight sleep of multiple physiological signals including electroencephalography (EEG), airflow, thoracic/chest or abdominal respiratory inductive plethysomography (RIP) effort signals, and oxygen saturation. The PSG test conducted at a sleep center facility is obtrusive and uncomfortable because they require an abundance of sensors and interfere with the person's sleep and prevent a representative sample of sleep from being obtained. The PSG test also involves high operating costs, in part because of the dedicated equipment, facilities, and personnel required to conduct the test. Additionally, the PSG test is time consuming and often varies based on the subjective interpretation of medical experts.
Therefore, there is a strong need for a solution that overcomes the aforementioned issues. The present invention addresses such a need.